Seven-year neurodevelopmental scores and prenatal exposure to chlorpyrifos, a common agricultural pesticide.
Level 3 - non-randomized controlled study
Prospective birth cohort follow-up study assessing prenatal exposure and 7-year cognitive outcomes.
PubMed 21507777 · doi:10.1289/ehp.1003160
What was done
In a prospective inner-city birth cohort of 265 children (Columbia Center for Children's Environmental Health), researchers measured prenatal chlorpyrifos (CPF) exposure using umbilical cord blood plasma (pg/g plasma). At 7 years of age, neurodevelopment was assessed using the Wechsler Intelligence Scale for Children, 4th edition (WISC-IV). Linear regression models estimated associations adjusting for maternal educational level, maternal IQ, and quality of the home environment, while testing for interactions with prenatal environmental tobacco smoke and polycyclic aromatic hydrocarbons.
What was found
On average, for each standard deviation increase in prenatal CPF exposure (4.61 pg/g), Full-Scale IQ declined by 1.4% and Working Memory declined by 2.8% at 7 years of age. No significant interactions were found between CPF and any covariates or other measured chemical exposures.
Why it matters
This study shows that cognitive deficits associated with prenatal organophosphate pesticide exposure persist into early school age, providing empirical evidence relevant to pesticide safety regulations.
Limits
The study is limited to a single inner-city cohort of 265 children, which may limit generalizability to rural agricultural or other demographics. Exposure assessment relied on cord blood plasma at birth, and exact confidence intervals or p-values are not reported in the abstract.
Cited by
- supports Research by Dr. Virginia Rauh at Columbia University demonstrated that higher levels of chlorpyrifos in umbilical cord blood correlate with lower IQ scores in children at ages 3, 5, and 7.